Jacob Amir (Spigler) - יעקב עמיר

Reaserch Projects

 

בחינת זנים של חיטה ושעורה

עמיר יעקב

בהתחלת שנות ה-60 נעשה השוואה בין דגנים מזנים שונים (זנים מחוץ לארץ וטיפוח מקומי). פרט לבחינת פוטנציאל היבול של הזנים השונים באזור הנגב הצפוני, ,נבדקה גם העמידות למחלות כמו חילדון ונבדקה רביצה ובכירות הזנים.טופחו זנים חדשים שהעלו את האיכות וכושר ההנבה בזנים הננסיים.

 

Ephrat,J.,Karchi,Z., Grama,A., and Amir,J. (1966).Experiment with new varieties of wheat1963/1964.Prelim.rep.no.524.Division of publication,Rehovot (in Hebrew

ניצול מי-נגר מאגנים קטנים למטרות חקלאיות

 

במשך ארבע שנים נאספו נתונים על אפשרויות ניצול מי נגר מאגני היקוות קטנים למטרות חקלאיות.

גשמים רצופים העלו את אחוז הניצול של המשקעים. גשמים קלים שירדו על מישטחים יבשים הקטינו את אחוז הניצול הממוצע. בשנים תקינות בנגב הצפוני (משקעים ממוצעים של 200 מ"מ) ניתן לצפות לתוספת של מים (50-70מ3 ) מפסים תורמים ברוחב של 2 מ`. הבעייה העיקרית היא ניצול של מי נגר הנאספים, במיוחד פיזור בשטח זרוע ומניעת התנקזותם בנקודות נמוכות. לא נמצא פתרון מניח את הדעת לבעיות אלה.

Amir,J.. (1966).Utilization of runoff from small water sheds for agricultural purposes.Ktavim 16:195-199 (in Hebrew)

 

מאזן המים ותרומתם המשקית של כרבים בנגב

עמיר יעקב

ניצול המישקעים בכרבים בנגב מגיע לכ- 50% מהכמות הכללית של גשמי העונה.התנקזות המים מתחת לשכבת הקרקע בעומק של 180 ס"מ היא איטית.כ 1/3 מהמשקעים הם זמינים.נבחן גורם הפוריות בניסויי דישון בכרבים ובשדות במחזורי גידול רצופים.תגובת החיטה לדישון, על גבי כרב נע,אינה גבוה.לאומת זאת היענות לדישון גבוה יותר כשהיא נזרעת על גבי סורגום או חיטה.תרומת הכרב לפוריות הקרקע היא טובה(הגדלת היבול),ובנוסף מספק מים לגידולים באיזוריים יבשים.

Amir,J.. (1966).The water budget on the evaluation of clean cultivated fallow in the Negev region..Ktavim 16:191-194 (in Hebrew)

 

השפעת מירווחי הזריע ומשטרי רטיבות שונים על גידול החיטה בנגב

עמיר יעקב

בשנת1960/61 נערך ניסוי במטרה לבדוק את שפעה של זריעת החיטה במשטחי רטיבות שונים ובמרווחים שונים בין שורות.לא היו הבדלים בכמויות המים המנוצלים ,בזריעה במרווחים השונים((5,30 ו45 ס"מ).

השפעת הרטיבות על מרכיבי היבול היתה בעיקר על משקל אלף הגרעינים ועל מספר השיבוליות לשיבולת.לא נמצאו הבדלים בין הטיפולים ה"יבשים" וה"רטובים" במספר השיבולים למ2. יבולי החיטה בטיפול הרטוב עלו באופן מובהק מאוד על היבולים של הטיפול היבש.בטיפול היבש גרמה הגדלת המירווחים לפחיתה מובהק הביבול.

Amir, J. (1962). Studies on the influence of soil moisture regime on the

yield of cereal in the Negev. Research and Experiments in the Negev.

Minhal Hadraha Negev Publication (in Hebrew).

 

 

מטבוליזם החנקן בעלי חיטה(Triticum aesativum L.) ההתפתחותם

עמיר יעקב

נחקרו השינויים המתרחשים במהלך התפתחותם של עלי חיטה עוקבים,בתנאי גידול שונים.בכל גיל נתון של העלים קיימת עלייה מתמדת בכמות החומר היבש שבעלים,מהבסיס אל קודקוד הצמח.מפל הפוך, מהקודקוד לבסיס,קיים לגבי תכולת החלבון והמים בעלים.

שימוש בחומצה אמינו מסומנת איפשרה בדיקת כושר האינקורפורציה כמדד לכושר הסינטזה של חלבונים בעלה.שיעור הסינטזה הגבוה ביותר נמצא בשלב הצמיחה החזקה של העלה.לאחר שלב זה מתחילה ירידה איטית בשיעור האינקורפורציה, עד למות העלה.לא נמצא קשר בין תכולת החלבוןברקמה לבין כושרה לסנטז חלבון.תכולת החנקן המסיס בעלים נשארה קבועה במשך כל תקופת חיי העלה.

הרחקת השיבולת עם הופעתה גרמה לבלימת תהליכי הפירוק,נעצרה גם הירידה(עם הגיל העלה)האיטית בשיעור האינקורפורציה של החומצה האמינית.מנגנון הסינטזה של החלבון אינומאבד מכושרו עם גיל הצמח. בצמחים חסרי השיבולת שגודךו בחדרי הצמיחה הזדקנו העלים מהקודקוד לבסיס("הזדקנות הפוכה").בתנאים טבעיים(בית רשת) לא היו תופעות של ("הזדקנות הפוכה".

Amir,J. (1968) Biochemical changes in leaves of wheat during development.

Ph.D. Thesis-Hebrew Univ.Ierusalem

Studies of wheat growing problems in Burma

J.Amir, Unla-Bow

This is a modest beginning of a moremethodical and basic investigation of the agricultural problems of Namsang.

 Sowing dates

1. Examination of the water balance of wheat crops during the dry season has shown that it is possible to obtain profitable yields even under exceptionally dry conditions, such as existed in1962/63, with September sowing dates.

High yields depend first and foremost on changing the sowing date to the first week of September. This will enable the wheat crop to develop its vegetative growth up to shooting by utilizing the rains at the end of the monsoon season, and later to use up

the water reserves that have meanwhile accumulated in the soil.

 2. The change of sowing date will enable better exploitation of fertilizers and the natural fertility of the top soil layer due to longer retention of soil moisture.

 3. The danger of frost during the earing-flowering period will also be prevented by changing the sowing date.

 4. Preceding crops: Changing the sowing date of the wheat crop necessitates a preceding summer crop that will leave the field free at the end of August. The most suitable crops in Namsang at present are soya, short-term Kenaf, ground nuts sown in the beginning of May, or green manure, if proved advantageous by experiments.

 5Fertility and manuring: The response to mineral fertilizers and to any other source of nutrients is very marked in Namsang soil. At the research station, where the level of soil fertility is higher than in the surrounding villages, the response to fertilization was also good. It is to be supposed, therefore, that in

the villages the response will be even greater. However, the key to efficient exploitation of fertilizers is moisture in the top soil layer.

Observations made at the research station and in the villages have shown that the application of organic manure is desirable under Namsang conditions. However, it should be applied to crops grown during the monsoon season and not directly to the wheat, which responds well to its residual effect also, even if it is the third crop in rotation after the organic manure application.

 6. Liming and pH: Response to lime was only noticed in those areas where the pH was between 5.0 and 6.0. In such cases application of lime very often doubled the yield. In areas with a pH value above 6.0, there was no response to liming. The pH values in the villages should therefore be thoroughly tested, so that lime will not be uselessly applied. In many instances we found pH values in the fields of villages 2 and 4 to be even higher than pH 6.0.

7.. Variety: At our present stage o:f knowledge the best variety that we have is Nanta 2419, which is rust-resistant and has a high potential yield.

The results o:f this study point to the possibility o:f growing wheat with considerable success in the Namsang region. It is a relatively easy crop to grow and moderate yields give an income equal to that :from ground nuts, which is the present cash crop.

The exploitation o:f the :fields in the dry season enables the :farmers

to grow two crops per year, thereby increasing their income considerably.

Amir, J. and Bow, Unla (1963). Studies on wheat growing problems in

Namsang Burma. Special Bull., Not. Univ. Inst. Agric., Rehovot.

 

Biological method for evaluating soil nitrogen

Amir,J.,Mufradi, I.,Kleitman,s.,Asido,S.

gilat method - part 1 - video

gilat method - part 2 - video 

After ten years of intensive research, a new biological method for evaluating soil nitrogen availability to plants was developed. The plant indicator.

approach developed in this method is applicable to other nutrients as well. After calibration and verification under field conditions, the 'Gilat Method'

was introduced on a commercial scale in 1979. In the last 10 years of

commercial use, the new test for nitrogen availability in the soil has saved

growers approximately $10 million. Even more important, the method

contributed towards a better survival strategy for drought years, which occur in

the Negev-Beer-Sheva area in 4 out of 10 years.

 Amir, J. and Ephrat, J. (1971). A biological method for evaluating soil

Nitrogen availability and forecasting nitrogen fertilizer needs of wheat.

Agronomy J. 63:385-388

Amir, L Ephrat, J. and Kafkafi, U. (1972). The evaluation of soil nitrogen

availability in the soil. Gan Sade V'Meshek No. 12: 260-623 (in

Hebrew).

Amir, J., Ephrat, J. and Kafkafi, U. (1973). The nitrogen evaluation in the

soil. Gan SadeV'Meshek No. 9: 356-359 (in Hebrew)

Amir, L Ephrat, J. and Kafkafi, U. (1972). The evaluation of soil nitrogen

availability in the soil. Gan Sade V'Meshek No. 12: 260-623 (in

Hebrew).

Amir, J. (1974). A biological method for evaluating soil nitrogen

availability. Proc.5th Israe lEcological Conf.H: 16-24.

Amir, J. (1975). Development of a biological method for evaluating soil

. available nitrogen. Plant Nutrition Symposium, Bet Dagan (in

Hebrew).

Vanunu.,E., Sadan, 8., Finkel, Y. and Amir, J. (1977). Evaluation of Gilat

method for evaluating nitrogen fertilizer needs for wheat in the

Negev. Gan Sade V'Meshek 926-629 (in Hebrew).

Amir, J., Mufradi, 1., Klitman, S. and Asido, S. (1993). Long-term

Comparitive study of soil nitrate test, Gilat plant indicator method and

wheat nitrogen uptake. Plant andSoil158: 223-231.

 

Interactive effect of water and nutritional stresses on wheat production in an aride zone.Long term multifactorial experiments at Gilat and Magen(1974-1996)

 link to related video

Amir,J.,Krikun,J.,Orion,D.,Putter,H.,Mufradi, I.,Kleitman,S.,Asido,S.

The objective of this project was to evaluate new agronomic strategies which might improve the water use efficiency of wheat in an arid environment. Among the important findings and accomplishments:

1. The discovery that the fallow management effect, of 104-220% more grain when compared with the continuous wheat cropping system, could not be attributed to stored soil water, since the fallow in the Negev-Beer-Sheva are is 'dry' (without available soil water). It was demonstrated that the beneficial effect of fallowing is the control of soil-borne pathogens. When the biocide methane-sodium was used to control soil pathogens, similar increases in yields were obtained with continuous wheat cropping management.

2. Another important finding of this study, was that the significant increase in yield after fallow period gradually disappeared in years with rainfall above 300 mm. This finding was the basis for the latest development – a new strategy for Negev dry land agriculture - which bypasses the soil sanitation problem by using no-till and mulch technology. By this new technology, two central problems that cause crop failures in arid regions (250mm and less annual rainfall), namely high soil evaporation losses and root pathogen damage, have been solved. In the last four years experience with the new technology, the rain water use efficiency (WUE) of continuous wheat has been improved from 0.5kg grain per 1000m2 per mm of rain to 1.0kg, which is equal to the WUE obtained from the fallow-wheat cropping system. However, 1993/1994 growing season was a severe drought year, caused by 163mm rainfall. Fields subjected to the new technology yielded 298kg of grain per 1000m2 in continuous wheat management, or WUE of 1.82kg of grain per 1000m2 per mm of rain. From a basic and applicative scientific point of view, this is a real break-through in the drought research, which allows production of economical cereal yield in drought prone regions. This achievement should be of enormous importance to alleviating world famine, the consequence of drought and improving the desertification process in arid zones.

3.In contrast to the unclear situation under dry land conditions in regard to the role of specific soil pathogens, it was found that under irrigation conditions the main soil pathogen was the fungus Gaeumannomyces graminis var. tritid (Ggt). The Ggt was discovered for the first time in the Middle East in our multi factor experiments.

 

Amir, J. and Vanunu, E. (1980). The effect of continuous wheat growth on. the wheat yields in the Negev. Gan Sade V'Meshek No. 10:1.4-22 (in

Hebrew). .

 

Amir, J. and Vanunu, E. (1980). Methods for continuous wheat growth on

the sandy soil of the Negev. Gan Sade V'Meshek No. 12: 9-15 (in

Hebrew).

Amir, J., Vanunu, E., Krikun, J., Orion, H.M., Penuel, D., Satki, Y.M. and

Lerner, A. (1981). Long-term experiment on dry-farming in the Negev

d~sert (1974-1980). A. The effect of continuous wheat system in a semi-

arid region. Hassadeh 62: 198-204 (in Hebrew with English abstract).

Amir, J., Vanunu, E., Krikun, H., Orion, D., Penuel, Y., Satki, Y. and Lerner,

A. (1981). Long-term experiment on dry-farming in the Negev desert.

B. The effect of winter fallowing in a semi-arid region. Hassadeh 62:

393-398 (in Hebrew with English abstract).

Amir, J., Vanunu, E., Krikun, J., Orion, D., Penuel, Y., Satki, Y. and Lerner,

A. (1981). Long-term experiment on dry-farming in the Negev desert.

C. Cereal nitrogen economy in a semi-arid region. Hassadeh62: 570-

576 (in Hebrew with English abstract).

Amir, J., Carmi, 5., Krikun, J. and Orion, D. (1982). Wheat agrotechnology

under arid conditions. Abstract of paper presented at the 'Gilfrid'

workshop on wheat, Tel Aviv.

Orion, D., Krikun, J. and Amir, J. (1982). Population dynamics of

' Pratylellchus thornei and its effect on wheat in a semi-arid region.

Abstract of paper presented at the meeting of UK Plant Pathology Society, Edinburgh, Scotland, UK.

Cohen, R., Krikun,J. and Amir,J. (1983). Take-alldisease in Israel.

. Hassadeh 63: 1182-1183. .

Orion, D., Amir, J. and Krikun, J. (1983). The nematode Pratylellchus thornei a dangerous pest to wheat in the Negev. Hassndeh63: 28-30.

Amir, J. (1984). Innovative management lor minimizing draught etlect in the Negev. Hnssadeh64: 1956-1960.

Amir, J., Krikun, J., Mufradi, I., Klitman, S. and Asido, 5.'(1987). Effect of soil sanitation conditions on wheat yields in the Negev. Israel Agresearc111: 15-21.

Amir, J., Krikun, J., Mufradi, I., Klitman, S. and Asido, S. (1987). Effect of soil sanitation conditions on wheat yields in the Negev. Israel

Agresearch1: 15-21.

Amir, J. Krikun, J., Orion, D. and Putter, J. (1988). Dry farming in an arid

environment. In: Unger, P., Sneed, T., Tordan, E. and Jensen, R. (eds.).

Challenges in Dryland Agriculture. Texas Agricultural Experiment

Station. pp. 183-186.

Amir, J. (1988). Promising technologies for arid zone crops. Water Irrig.

Rev.7: 19-21.

Amir, J., Krikun, J., Orion, D. and Putter, J. (1991). Dry farming in an arid

environment. 1. Water use efficiency of wheat management practices. Field Crops Res. 27: 351-364.

Amir, J., Krikun, J., Orion, D., Putter, H. and Klitman, S. (1991). Dry

farming in an arid environment. 2. The role of soil pathogens. Field

Crops Res. 27: 365-376.

Orion, D., Amir, J. and Krikun, J. (1993). Field observation on Pratylencus

thornei.. Rev. Nematol. 7: 341-345.

Amir, J., Mufradi, 1., Klitman, S. and Asido, S. (1993). Long-term

Comparitive study of soil nitrate test, Gilat plant indicator method and

wheat nitrogen uptake. Plant and Soil158: 223-231.

Amir, J. and Sinclair, T.R. (1994): Cereal grain yield: Biblical aspirations

and modern experience in the Middle East. Agronomy J. 86: 326-364

Amir, J. (1994):. Impact of crop rotation on soil erosion and rehabilitation.

In: Agassi, M. (ed.). Soil Erosion, Conservation and Rehabilitation.

Marcel Dekker, Inc., New York

Amir, J. (1994). Brought up-to-date the introductory chapter in the winter

cereal production. In: The Encyc1opedia of Agriculture. 4:51-58

Amir, J. (1994). Brought up-to-date the wheat chapter.

In: The Encyclopedia of Agriculture. 4:58-67

 

Amir, J., Krikun, J., Gnizi, A., Penuel, Y., Naptaliyahu, U., Mufradi, I.,

Klitman, S. and Asido, S. (1995). Long-term experiment on dryland

farming in the Negev. Gan Sade V'Mesllek . 3:19-22

Amir ,J(1996) . A new technology of non-tillage and soil covering in Negev cereal culture.Hassadeh 76:51-56

Amir,J., Thomas R. Sinclair (1996)A straw mulch system to allow continuous wheat production in an arid climate .Field Crops Res.47:21-31

Amir ,J., Thomas R. Sinclair (1996)Cereal cyst nematode effects on wheat water use, and on root and shoot growth .Field Crops Res 47:13-16-9

No'am G. Seligman,Abraham Blum,Josep Morin and Jacob Amir(1997)

Agricultural development in Israel: Challenges and opportunities for

regional collaboration. In:American Journal of Alternative Agr.12:120-124

Amir, J. and T. R. Sinclair (1997)Doubled wheat production in an arid environment using conservation tillage. Tred in Agronomy 1:46-50

 

 

Mechanistic model describing growth and yield of wheat

J. Amir, T.R. Sinclair

A simple mechanistic model was developedand employs an intermediate approach between the regressionmodel and complex models. It uses a few conservative relationships todescribe crop ontogeny, growth and seed production. Test and validation ofthe model was done against data collected in ten years of Gilat long-term

multi-facto~ experiments in Israel. Observed field response to varying water

and nitrogen treatments were well simulated by the new model. Our

simulation models and the sensitivity tests were presented to interested

agencies in the US Department of Agriculture by Prof. T. Sinclair

 

Amir, J. and Sinclair, T.R. (1991). Temperature and solar radiation effects on the growth and yield of spring wheat. Field Crops Res.28: 47-58.

Amir, J. and Sinclair, T.R. (1991). Waler limitation on tIhe growth and yield of spring wheat. Field Crops Res.28: 59-69.

Sinclair, T.R. and Amir, J. (1992). A model to assess nitrogen limitations

on the growth and yield of spring wheat. Field Crops Res. 30: 63-78.

Amir ,J. and Sinclair, T. R. (1996)Cereal cyst nematode effects on wheat water use, and on root and shoot growth Field Crops Res 47:13-16-9

J. Amir and T. R. Sinclair (1997)Doubled wheat production in an arid environment using conservation tillage. Tred in Agronomy 1:46-50

 

Extension of 'Gilat Method' for prediction of available phosphorous and

potential cereal nematodes infestation in the soil

J. Amir, I. Mufradi,S. Kleitmam,S. Asido

The soil samples from 500.00 dunam, brought to Gilat each year for evaluation

of available nitrogen, will be used to supply additional information about

available phosphorous and cereal nematodes infestation in the soil. The new

method passed the calibration and validation tests in the laboratory and under

field conditions, and are available for commercial use.

Jacob Amir, Thomas R. Sinclair (1996)A straw mulch system to allow continuous wheat production in an arid climate .Field Crops Res.47:21-31

 

New technology for achieving economical yields of cereal in drought years in_the Negev

Amir,J., Krikun,J., Orion,D., Putter,H., Mufradi, I., Kleitman,S., Asido,S.

At present there are few agro-technologies for preventing crop failure in arid regions (250mm and less annual rainfall). Low annual rainfall, unpredictable seasonal distribution and poor soil sanitation conditions are the main limiting factors in achieving economical cereal yields. A wheat-fallow rotation ha~ been the most successful crop management till now. However, from a sustainable,

economical and ecological point of view, this type of management has not

proved to be tenable, and the need for a better solution has been long recognized. Twenty years of research by a multidisciplinary team, lead by Dr. Jacob Amir, has resulted in a successful development of a new agrotechnology, based on no-tillage and soil mulch management. This way, the two central problems that cause crop failure in arid regions, high soil evaporation and root pathogen damage, have been solved. In the last three years experience with the new management, the yield of continuous wheat was equal to theyield obtained from fallow-wheat management (both approximately 250kg per1000m2). This achievement should be of enormous importance for the Negev region and other drought prone areas in the world

 

Amir, J. (1994):. Impact of crop rotation on soil erosion and rehabilitation.

In: Agassi, M. (ed.). Soil Erosion, Conservation and Rehabilitation.

Marcel Dekker, Inc., New York

Amir ,J(1996) . A new technology of non-tillage and soil covering in Negev cereal culture.Hassadeh 76:51-56

J. Amir and T. R. Sinclair (1997)Doubled wheat production in an arid environment using conservation tillage. Tred in Agronomy 1:46-50

 

Other research programs

השפעת פיצול גופרת אמון על יבול התרמילים של אגוזי אדמה בקרקע לס

י.,עמיר, ד.,לחובר

ב-1960 נערך ניסוי דישון אגוזי אדמה בקרקע לס, במטרה לבדוק את השפעתן על מנותשונות של גופרת אמון,הניתנות כדשן-יסוד וכדשן ראש,על יבולי התרמילים.כל טיפולי הדישון שבניסוי הגדילו באופן מובהק את היבול בהשוואה לביקורת.תוספת של גופרת אמון כדשן ראש לדשן –יסוד,הגדיל את היבול באופן מובהק בהשוואה לדישון בכמות כפולה כדשן יסוד.

בבדיקות העלים שבוצעו בראשית הפריחה לא נמצא קשר בין ריכוז החנקן בעלים לבין טיפולי הדישון,ואף לא בינו לבין הביקורת.

Amir, J. and Lachover, D. (1963). The influence of split applications of

ammonium sulfate for peanuts In loess soil. Hassadeh 33: 1400-1402

 

ניסויי השוואה על השפעת זבל ירוק,כרב תחמיץ ודישון חנקתי על יבול אגוזי אדמה

י.עמיר,ד.לחובר, א.גולדין

נערכו ניסויים בקרקע לס לבדיקת השפעתם של זבל ירוק,כרב תחמיץ ודישון חנקתי על יבול אגוזי אדמה.לא נמצאו הבדלים מובהקים בין יבולי הביקורת0 טיפול משקי) לבין יבולי החלקות שקיבלו זבל ירוק עם או בלי תוספת דשן חנקתי.

בטיפול כרב התחמיץ התקבלו יבולים נמוכים( באופן מובהק) בהשוואה לטיפול הביקורת ודישון בזבל ירוק. תוספת דשן חנקתי לכרב התחמיץהגדילה את היבול(השוותה אותו ליבול הביקורת)

לא נמצא יתרון לזבל הירוק או לכרב התחמיץ על פני השיטה המקובלתשל דישון חנקתי בקרקע לס.

J Lachover, D., Amir, J. and Goldin, E. (1963). Influence d'engrais verte et

d'engrais azotee sur le rendement et la qualite des arachides.

Oleangineaux 18: 153-156.

Lachover, D:, Amir, J. and Goldin, E. (1963). The influence of green manure in peanuts. Hassadeh, 33: 1-3 (in Hebrew).

 

Difficulties in determining the nitrogen fertilizer requirement of peanuts by foliar diagnosis

J. Amir, D. Lachover. W. E. Goldin

At the Gilat Experimental Farm in the northern Negev peanut samples were taken during three years of nitrogen and phosphorus trials in order to test the use of foliar analysis as a diagnostic tool for determining the nitrogen requirement of the crop.

Several different ways of interpreting the nitrogen foliar diagnostic results were studied in order to discover the most suitable index for the expression of the

nitrogen requirement peanut plants.

No significant correlations were found between weight of leaf sample, or

fertilizer treatment or yield and the nitrogen concentration in the leaves.

It is suggested that the lack of correlations may be attributed to the steadily rising

fertility level of the experimental fields during the course of three seasons. The

validity of this assumption seems to be supported by the following facts, which emerged from three years of experimentation:

a. control (without nitrogen) plot yields rose steadily during the three seasons;

b. each year's correlation curve between leaf nitrogen values and nitrogen

fertilizer rates shows a characteristic increase in the leaf nitrogen

content from year to year;

c. the pattern of pod-yield values when related to leaf-nitrogen content shows

a restricted scatter which is characteristic for each experimental year and

again demonstrates the rising level of fertility during the course of these

experiments.

 

Amir, J., Lachover, D. and Goldin, E. (1964). Difficulties in determining the

nitrogen fertilizer requirement of peanuts by foliar diagnosis. Prelim.

Rep. No. 445. Division of Publication, Rehovot.

 

Experiments on peanuts cultivation in a loess soil

S.Dasberg, J.Amir

1. In 1960 and 1961 experiments were carried out at the Gilat expe;t"imental farm

to test the effect of land preparation and cultivation during . the grdwing season "

on peanut yields and soil structure.

 2. In the first year experiment no favorable effect on crop yield was obtained

with land preparation and cultivati.:on. Plots prepared'to a depth of 45 cm and

cultivated during the growing season produced yields similar to those of the'

control plots; which were only til!ed to a depth of 15 cm and not cultivated.

 3.In the second season depth of land preparation again had n'o influence on crop

yields and soil bulk density. It was found however that cultivation had a

favorable effect on soil structure; bulk density of the upper soil layer and

resistance of the soil to penetration were lowered by the cultivation

treatments.

4. Control plot yields in 1961 were significantly higher than those of the

cultivated plots. No differences between deep and shallow cultivation were

obtained. Three additional cultivations (to the four regular ones) caused a

further reduction in yields. The probable explanation for these facts is

mechanical damage to plants by cultivation implements.

5. No measurable effect of land preparation and cultivation treatments on soil

water relations was obtained.

 

Dasberg, S. and Amir, J. {1962). Experiments on peanut cultivation in a loess soil. PreIim. Rep. No. 393. Division of Publication, Rehovot (in Hebrew).

Dasberg, J. and Amir, J. (1964). Tillage experiments with peanuts

Agronomy J. 56: 259-262.

  

A Study on the Reproductive Stage of the Groundnut,

Arachis hypogaea L.

Induction of pod setting in the upper-nodal gynophores1

J.Amir

In groundnut plants growing under controlled conditions it was possible to

induce pod-setting of the upper-nodal gynophores, which do not normally set

pods, by forming a two-level surface of the rooting medium and by treating the

gynophores with gibberellic acid. There was no inhibitory effect on the pod-setting

of these gynophores by the pods developing on the basal-nodes; the setting

of the upper-nodal pods reduced the yield of the basal nodal pods, and the

potential yield was not increased. The activation of the upper-nodal gynophores

was associated with a prolongation of vegetative growth and flowering, and with

an increase in fresh and dry weight of roots and tops. Pod filling was inferior in

comparison with field conditions, possibly because of low light intensity. Direct

application of gibberellic acid to the upper-nodal gynophores caused the elongation.

of these as well as of the basal-nodal gynophores which were not treated.

 

. Amir, J. (1969). A study on the reproductive stage of the groundnut, Arachris hypogaen. Ann. Bot. (N.s.) 33: 333-338.

 

Weed control of irrigated peanuts in an arid zone

Amir J.

In a  cooperative program with a weed researcher, we evaluated chemical weed control possibilities for peanut , aiming to replace costly manual 

weeding, which required 5-7 workdays per 1000 m2. The best weed control was achieved using a combination of two herbicides-alachlor and

terbutryn. In 1974, we introduced the new herbicid,

glyphosphate as a preemergence treatment, and this herbicide kept the

fields completely clean of C. dactylon ford a period of two years.

 Amir, J. (1964). Weed control experiments in peanuts. Proc. 1st Weed

Control Conference 1: 139 (in Hebrew with English abstract).

 Hurwitz, N. and Amir, J. (1965). Experiments on the control of weeds in

peanuts. Hassadeh 35: 663-666(in Hebrew).

Amir, J., Lachover, D. and Goldin, E. (1965). Experiments on the influence

of green-manure and nitrogen fertilizer in peanuts. Research and

Experiments in Peanuts, Agricultural Publication Division No. 614,

Hakyria, Tel Aviv (in Hebrew).

Amir, J. (1965). Research and Experiments in Peanuts, pp. 63-67.

Agricultural Publication No. 67, Hakyria, Tel Aviv (in Hebrew).

Amir, J., Vanunu, E., and Lifshitz, N. (1975). Control of .Cynadon datylon L. Pers. in peanuts with glyphosate. Proc. 6th Israel Weed Control

Amir, J., Vanunu, E. and Lifshitz, N. (1977). Trials with glyphosate to control Cynadon dactylon in peanut in the Negev. Hassadeh 58; 2323-2326.

 

Tillage experiments with peanuts

Amir J.

Beginning in 1960 ,a co-worker an I investigated the assumption that

peanuts exert specific demands on the physical condition of the soil to

allow penetration of the pegs. The recommended practice in Israel was

deep soil preparation (25-35 cm) with frequent deep inter-row cultivation.

The most striking result of these experiments was out finding that, although different tillage treatments were effective in reducing soil strength and bulk density, no significant effect on plant yields was obtained. The peanut yields decreased as the number of inter-row cultivations was increased.

 Dasberg, S. and Amir, J. {1962). Experiments on peanut cultivation in a loess soil. PreIim. Rep. No. 393. Division of Publication, Rehovot (in

Hebrew).

Dasberg, J. and Amir, J. (1964). Tillage experiments with peanuts

Agronomy J. 56: 259-262.

Dasberg, M. and Amir, J. (1965). Research and Experiments in Peanu!s, pp.

63-67. Agricultural Publication Division No. 67, Hakyria, Tel Aviv (in

Hebrew)

 

The influence of various soil moisture-regime on the yield and quality of cotton in an aride zone

Amir J. and Bielorai H.

The results of three cotton irrigation experiments in the Negev region indicate that by increasing the intervals between irrigations and by applying the first irrigation at the beginning of flowering ,maximum yields of 1700-2100 kg/ha can be obtained with three irrigations. In all treatments except the one with four irrigations, about 0.31 kg of lint was produced for each 1 m3 of irrigation water. In the three driest treatments, where cotton suffered from moisture stress during various periods of growth, no differences in lint quality could be detected in comparison with wetter treatments. As long as there were clear drought symptoms, such as in the three driest treatments, additional irrigation increased the number of bolls/plant, while the average boll weight remained unaffected. Additional irrigation in treatments where there were no clear water stress symptoms did not increase the number of bolls/plant, but increased the average boll weight.

 

Amir, J. and Bielorai, H. (1969). The influence of various soil moisture

regimes on the yield and quality of cotton in arid zone. J. Agric. Sci. 73:

425-429.

 

  C hemical control of sucrose convertion to polysaccarides in sweet corn after harvest

J.Amir and J.Cherry

 The project was carried out in a cooperative program with Purdue university researchers and was financed by the General Food Corporation USA.

Among the original findings of this period:

a) Pyrophosphate was found to be the most effective agent in maintaining the amount of sucrose after harvest. The effect of pyrophosphate treatment is interpreted as an product inhibition of nucleotide diphosphate-glucose synthesis.

b) An alternative method found was in treatment of corn cobs with a chelating agent (e.g., disodium salts of ethylenediamine tetra-acetic acid).

The chelating agents enhance the translocation of sugar from the parenchima tissue to the endosperm tissue of the corn kernel. The results were patented by the Purdue Research Foundation and used by General Food Corporation.

 

Amir, J., Wright, H. and Cherry, J. (1970). Regulation of sugar conversion

to polysaccharides in sweet corn. Plant Physiol. 46: 5-27.

Amir, J. and Cherry, J. (1971). Properties of purified ADP - glucose

pyrophosphorylase from sweet corn: Pyrophosphate inhibition. Plant

Physiol. 47: 5-5.

Amir, J., Wright, R. and Cherry, J. (1971). Chemical control of sucrose

conversion to polysaccharides in sweet corn after harvest. J. Agric. and

Food Chem. 19: 954-957.

Amir, J. and Cherry, J. (1972). Purification and properties of/ADP-glucose

pyrophosphorylase from sweet corn. Plant Physiol. 49: 893-897.

Amir, J. and Cherry, J. (1972). Sucrose accumulation in sweet corn kernels: Effect of chelators. J. Agric. and Food CIlC11l.20: 785-787.

Amir, J., Cherry, J. Methods of increasing accumulation in plant storage organs. United State Patent 3.937.837, 1974,Washington, DC.

 

 

Prevention of sugar accumulation in cold stored potato

J. Amir, V. Kahn

The second stage of the research on control of starch –sugar conversion in plants, involving low temperature effect on sugar-starch conversion on potato ,was performed in Israel in cooperation with the division of food technology, and supported by a grant from the US-Israel Binational Science Foundation. The findings of major importance in this multi-disciplinary project were:

a) As a result of the need to study the starch-to-sugar conversion. in the

absence of complications introduced by budding (sprouting), ., new, inexpensive and simple method of chemically debudding potato was developed. The method opened the way in permitting careful studies of aging process in tubers during storage at any temperature, and therefore was a key technological advance .

b) A brief period of controlled anoxia can cause a long-lasting inhibition

of the starch-to-sugar conversion during cold storage. The method proposed was inexpensive, effective, and could be readily adapted to commercial use .

Amir, J., Kahn, V. and Unterman, M. (1976). Prevention of sugar

accumulation in cold-stored potato. Abstract of papers presented at the

meeting of Botanical Society of Israel. Tel Aviv University (in Hebrew

with English abstract).

Amir, J., Kahn, V. and Unterman, M. (1977). Sugar accumulation in

chemically debudded tubers during cold storage. Phytochemistry 16:

1603-1604. '

Amir, J., Kahn, V. and Unterman, M. (1977). Respiration, ATP level, and , t

sugar accumulation in potato tubers during storage at 4°. V

Phytochemistry 16: 1495-1498.

Amir, J. and Kahn, V. (1978). Means to prevent starch to sugar conversion.

Fifth Iternational Congress of Food Science and Technology, Kyoto,

Japan, pp. 193.

Kahn, V., Goldschmidt, S., Amir, J. and Granot, R. (1979). Some

biochemical properties of soluble and bound potato tuber peroxidase. J.

Food Sci. 46: 756-764.

 

The kinetic characterization of spinach leaf sucrose-phosphate synthetase

 J. Amir, J.,Preiss

 The biochemical work on the enzyme involved in starch-to-sugar conversion was continued during a sabbatical year at the Dept. of

Biochemistry and Biophysics, University of California at Davis. In

cooperation with Prof. Preiss, we studies the kinetics and properties of leaf

sucrose-phosphate synthase. The principal results obtained were:

 

a) Sucrose-P-phosphate synthase is an important regulatory enzyme,modulated by the fructose-6-P /Pi and UDP glucose/Pi ratios in the cellcytoplasm.

 b) Of particular interest was the inhibition of the leaf sucrose-P-syuthase by (pyrophosphate (Pi). This inhibitory is quite effective in the range 5 to 10mM.

 c) The inhibitor is competitive with UDP glucose, and it also slightly decreases the apparent affinity for the fructose-6-P as the substrate S0.5 value (concentration of substrate giving 50% of maximal velocity,

increased from 3.0 to 5.9 mM).

 

Amir, J. and Preiss, J. (1982). The kinetic characterization of spinach leaf sucrose-phosphate synthetase. Plant Physiol. 69: 1027-1030.

 

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