نشریه علوم به زراعی گیاهی
سال دهم شماره 2 (پاییز و زمستان 1399)

In order to evaluate different planting dates in wheat cultivars on yield and remobilization of dry matter in the crop year 1396-97 in Ahvaz in the form of split plots in a randomized complete block design with three replications. the main factor included three planting dates of December 11, 31 December and January 20 and the sub-factor included four bread wheat cultivars Chamran-2, Sirvan, Mehregan and Chamran. the results showed that the effect of planting date and cultivar on current photosynthesis rate, current photosynthesis efficiency, remobilization rate and remobilization efficiency was significant at 1% level and the interaction effect of planting date and cultivar on grain yield and biological yield was significant at 1% level. the highest grain yield was obtained on planting date of December 11 and Chamran-2 cultivar (5420 kg/ha) while the lowest grain yield was obtained on planting date of 31 December and Sirvan cultivar (2660 kg/ha). the highest amount of remobilization was obtained from the date of planting on December 11 (153.45 g/m2) and the lowest rate was obtained from the date of planting on January 20 (100.25 g/m2). as a result, the planting date of December 11 was superior to other planting dates due to the provision of suitable temperature and radiation conditions in the vegetative and reproductive period and its favorable effect on yield and dry matter transfer of wheat in Chamran-2 cultivar.

In order to evaluate of effects, the nitrogen and potash fertilizer on yield, yield components and remobilization on number 4 rice promising line. The study was conducted using a factorial experiment arranged in completely randomized design with three replications at the Rice Research Institute of Iran in 2012. The factors were nitrogen with 3 levels (60, 90 and 120 Kg.h-1) from Urea fertilizer’s resource and Potash fertilizer with 3 levels (0, 50 and 100Kg.h-1) from the sulfate potash resource. Analysis of variance showed that the Nitrogen Factor was significant on all the considered traits at 1 probability levels. The Potash Factor was significant on the grain 1000 weight at 1 probability level. The interaction effect of Nitrogen in Potash on traits the number of filled grain and the grain 1000 weight were showed significant difference at 5 probability levels. The highest of treats seed yield (7818 kg.h-1), the percentage of panicle reproduction (88.47%), grain 1000 weight (30.08g), the number of seed filled (149.4), height plant (110.6 cm) and for remobilization of dry matter (1198g.m-2) were obtained 120 kg. ha-1. Mean comparison effects of Nitrogen in Potash interactive showed that for grain yield of a 120 kg nitrogen per 50kg Potash with the average of 7994 kg h-1 was consider a higher class. Finally, for the number 4 promising line of rice can use a level of fertilizer which includes 120 kg pure Nitrogen (260 kg urea fertilizer) and 50 kg Potash (100 kg super triple phosphate fertilizer) per a hectare.

Salinity stress is a major problem of limiting agricultural productivity and plant growth in many regions of the word including Khuzestan. There are various practices that can apply including Improvement of saline soils and irrigation management and introduction of toleratedcultivars. The aim of experiment is introducing tolerant and semi tolerant cultivars in many regions for acceptable crop yields. Breeding for salinity tolerance, pot experiment under natural conditions in a completely randomized design and enforced in three replications in three states in a stress, fourteen ds/m and twenty-one ds/m. Genotypes were evaluated for salinity tolerance by using dry matter of grain, seed number, grain yield, 1000-grain weight, and relative water content, leaf Na+, leaf K+, leaf K+/Na+. Sirvan cultivar at both salinity levels 14 (17.30 mg / g) and 21 (28.43 mg / g) ds/m, had the highest amount of leaf sodium and aflak cultivar (8.70 mg / g dry weight), had the lowest sodium concentration under 21 ds/m salinity stress. According to the results, among the genotypes studied, aflak as resistant cultivar, Sirvan as susceptible and Arg cultivar as a medium were selected from varieties adapted to Khuzestan conditions.

The use of nanofertilizers and planting date might improve potato performance. In order to study nitrate accumulation and yield changes of potato tubers using different concentrations of iron (Fe) and magnesium (Mg) nano-particles in cultivation date of "Sante" cultivar, a split-split plot based on randomized complete blocks design with three replications were carried out in Research Farms of Jihad Keshavarzi located in Islamabad and Zeh-e Kalut region of Kerman province.Area as main factor and sub-factor including spraying of Fe and Mg nanoparticles (0, 1 and 2%) at flowering and tuber filling stages and sub-sub plot include two planting dates (5 and 25 October) were investigated.Results showed that mean tuber weight was significantly affected by different treatments of nano-particle spraying (p < 0.05).Effect of experimental treatments (area and date of planting) and their two and three effects was non-significant on tuber weight (p>0.05), but on yield were significant (p < 0.01). The highest yield was related to 2% spraying of Fe+Mg nano-particles on 5 October in Zeh-e Kalut area. Also, the highest tuber nitrate was obtained in control (spraying with distilled water) treatment. 1% Fe nano-particles and 1% Fe nanoparticle+2% Mg nanoparticle was divided into a single statistical group and showed significant difference with other treatments (p < 0.05).For all measured traits, it seems that the use of low consumption and essential elements through preservation of leaf greenness, improvement of photosynthetic system and increasing leaf durability led to increase length of tuber filling and tuber conversion and decrease in tuber nitrate.

In order to determine the best sowing date in two soybean cultivars, an experiment was done in Ramhormoz Agricultural Research Farm in split plots on the basis of randomized complete blocks design with three repetitions in 2017. Treatments includes three planting dates 1 August, 16 August, 1 September were placed in the main plots and two soybean varieties including 504 and Saland in subplots.Results showed that planting date had significant effect on plant height, number of pod per plant, number of seed per pod, number of seed per plant, number of plant per square meter, harvest index and seed protein percent. The effect of cultivar was significant on plant height, number of seed per pod, number of plant per square meter, total dry weight, biological yield and grain yield. Saland cultivar in the second planting date produced the highest 1000-grain weight with an average of 148.2 g and on the third planting date, the smallest one was obtained with an average of 103.8 g. Saland cultivar in the second sowing date had the highest grain yield (2059 kg. ha-1) and the highest biological yield (3305 kg. ha-1). In the third planting date, Saland cultivar yielded the lowest grain yield (506 kg. ha-1) and the lowest biological yield (954.3 kg. ha-1).Seed oil percentage was not significant in any of treatments, but in the third planting date it was less than two other planting dates. Seed protein percentage was affected by planting date and in the third planting date its reduction was significant.Thousand-grain weight had significant positive correlation with grain protein percentage at 1% probability level, which indicates that with increasing grain weight, more protein is stored in the grain.In general, it is possible to recommend Saland cultivar for sowing date in 16 August and 504 for sowing date in 1 August and 1September.