اثر تاریخ کشت و تراکم بوته بر ویژگی‌های رشدی و اجزای عملکرد گوار(cyamopsis tetragonoloba l.) در منطقه بیرجند

به‌منظور بررسی اثر تاریخ کاشت و تراکم بوته بر گیاه گوار (cyamopsis tetragonoloba l.) آزمایشی به صورت کرت‌های خرد شده در قالب طرح بلوک‌های کامل تصادفی با سه تکرار در سال 1398 در ایستگاه تحقیقات کشاورزی محمدیه بیرجند انجام شد. عوامل آزمایش شامل تاریخ کاشت در چهار سطح (10 اردیبهشت،10 خرداد، 25 خرداد و 10 تیر) به‌عنوان کرت های اصلی و تراکم در سه سطح (تعداد 11، 17 و 33 بوته در مترمربع) به‌عنوان کرت های فرعی در نظر گرفته شدند. اثر متقابل تاریخ کاشت و تراکم بوته بر روی صفت تعداد غلاف در بوته در سطح یک درصد معنی‌دار و بر روی سایر صفات اثرات معنی داری نداشتند. بیشترین تعداد غلاف در بوته از تاریخ کاشت 10 خرداد و تراکم 11 بوته در مترمربع با افزایش 6/249 درصدی نسبت به کمترین تعداد غلاف در بوته از تاریخ کاشت 10 اردیبهشت ماه در تراکم مشابه حاصل گردید. اثرات اصلی تاریخ کاشت و تراکم بوته بر روی کلیه صفات به‌ترتیب به‌جز تعداد شاخه فرعی در بوته و طول غلاف و نیز تعداد دانه در غلاف معنی‌دار بود. بیشترین میزان صفات رشدی و عملکردی از تراکم 33 بوته در مترمربع و از تاریخ کاشت 10 خرداد ماه به دست آمد. به‌طوری‌که عملکرد دانه در تاریخ کاشت 10 خرداد ماه از افزایش 3/79 درصدی نسبت به تاریخ کاشت 10 تیر ماه برخوردار بود و این کاهش عملکرد می‌تواند به‌دلیل برخورد گیاه با دمای نامناسب آخر فصل باشد. با توجه به نتایج آزمایش، می توان بیان کرد که افزایش تراکم گیاهی منجر به افزایش عملکرد دانه و عملکرد بیولوژیک در واحد سطح گردید، بنابراین می توان چنین نتیجه گرفت که بر اساس شرایط و نتایج این آزمایش، اگر گوار در اوایل خرداد ماه و با تراکم 34 بوته در مترمربع کشت گردد، افزایش عملکرد و اجزای آن دور از انتظار نخواهد بود.

effect of planting date and plant density on growth characteristics and yield components of guar (cyamopsis tetragonoloba l.) in birjand region

introductionthe growing global population, coupled with the scarcity and limitations of food resources, has prompted researchers and agricultural professionals to seek more effective solutions for feeding millions of people, particularly in developing countries. guar (cyamopsis tetragonoloba l.) is an annual legume known for its tolerance to salinity and drought, making it a promising alternative crop for low-water plains. determining the appropriate planting date and optimal plant density are crucial factors that contribute to the efficient use of environmental resources and achieving high yields. materials and methodsthis experiment was performed in the form of split plots based on a randomized complete block design with three replications in 1398 in mohammadieh agricultural research station, birjand. experimental factors include planting date in four levels (may 10, june 10, june 25 and july 10) as main plots and plant density in three levels (distances of 10, 20 and 30 cm between plants in a row) as plots guar cultivar was a pakistani mass that was prepared from pakan bazar isfahan company. for planting, the land was plotted after preparation so that each plot consists of 4 ridges 60 cm wide and 3 m long, and on each row of two rows was planted manually at a depth of five centimeters, and irrigation was carried out immediately. after reaching the final height of guar plant and physiological maturity before final harvest, taking into account the marginal effect of five plants from each plot, they were randomly selected and the characteristics of plant height, number of sub-branches per plant, pod length, number of pods per plant, number pods per plant, 1000-seed weight, initial plant weight, plant weight without pods and pod weight were measured. the number of pods per square meter, plant yield, and biological yield were calculated after removing the marginal effects based on plants harvested from one square meter in the middle of each plot. data were analyzed using sas software (v9.1) and comparisons of means were performed by duncan method at 5% level and graphs were drawn with excel.results and discussionone of the most important fields of research on legumes is the study of different environmental conditions affecting their quantitative (biological) yield and economic performance. therefore, studying and obtaining the best growing environment conditions that can lead to crop production with the highest economic yield is one of the most important goals in research related to the cultivation of legumes. the results of the present study showed that seed yield and its components were affected by planting date and with delay in planting, the amount of studied traits was significantly reduced, so that this decrease was more in the planting date of 10 july because the planting date late exposure of guava plants to adverse conditions such as lower temperature, more humidity and less day length at the end of the growing season and causes a decrease in grain yield. also, in this experiment, planting density levels on the studied traits were significant, and according to the results of the experiment, it can be stated that with increasing plant density, the distribution of sources such as light, nutrients, and moisture between plants was more favorable. it led to an increase in grain yield and biological yield per unit area, so that the highest grain yield and biological yield were obtained at the highest density (10 cm distance between plants per row). therefore, planting at higher plant densities will probably be economically justified. conclusionsbased on this research, it can be concluded that planting guar in early june with a spacing of 10 cm between plants yields the highest productivity and optimal crop components.