Journal of Crop Nutrition Science
Volume:10 Issue: 3, Summer 2024

Fertilizer management is one of the most important factors in successful cultivation to improve quality and quantity of crop production.

In order to examine the effects of different levels of zinc fertilizer on yield of different barley cultivars, this study was done in the agricultural year 2020-21 in Susangerd County.

Current research was conducted by using split plots within a randomized complete block design with three replications. The main plots consisted of three barley cultivars (13 Sarasari, 10 Sarasari and local Susangerd), and the subplots included different levels of zinc fertilizer (Z1=0, Z2=20, Z3=40, and Z4=80 ZnSO4 kg.ha-1).

The results indicated that the highest number of spikes belonged to the local Susangerd cultivar (375.2) and 10 Sarasari (277.6), and also the highest number of grains per spike and 1000 grain weight were attributed, in order, to the 10 Sarasari and 13 Sarasari cultivars (40.17) and (53.6). The highest number of spikes, number of grains, and 1000 grain weight were achieved with the consumption of 80 kilograms of zinc per hectare. The interactive effects of treatments were not statistically significant for any of the examined traits.

Overall, considering the environmental conditions of the southern Khuzestan province and the deficiency of zinc in the soils of this region, the use of zinc fertilizer can be effective in improving the grain yield of cereals in the province.

In order to investigate the effect of humic acid foliar application on the yield and yield components of cowpea under low irrigation conditions in the south of Khuzestan, an experiment was designed and implemented in the form of one-time chopped plots in the form of a randomized complete block design with three replications. The main factor included different levels of low irrigation (70 (control), 90, 110, and 130 mm of evaporation from the surface of the Class A evaporation pan) and the secondary factor included different amounts of humic acid fertilizer (including consumption of zero, 4, and 6 liters per hectare). The difference between different levels of low irrigation and humic acid in terms of plant height, pod length, number of sub-branches, number of pods per plant, number of seeds per pod, weight of 1000 seeds, seed yield, biological yield and harvest index are statistically significant at the probability level of 1 % was significant. The interaction effect of treatments on plant height and number of pods per plant was significant at 1% probability level and pod length, 1000 seed weight and seed yield was significant at 5% probability level. The highest seed yield belonged to the irrigation treatment of 70 mm evaporation and foliar spraying with 6 liters per hectare with an average yield of 3755 kg per hectare. The lowest seed yield was obtained from the irrigation treatment of 130 mm of evaporation and without foliar spraying with an average of 987 kg/ha. The highest and lowest harvest index belonged to the irrigation treatment of 70 and 130 mm of evaporation from the pot, respectively (with an average of 41.25 and 25.67 percent). Based on the results of the research, foliar application of 6 liters per hectare of humic acid at different levels of low irrigation increased seed yield compared to the control (no foliar application).

Correlation and path coefficient analysis could be used as an important tool to evaluate relation between traits, propose most effective trait on seed yield and determine direct and indirect effects of selected traits on dependent variable. Evaluate correlation be-tween traits and selected effective traits those had the highest effect on seed yield by stepwise regression and determine direct and indirect effect of selected traits on seed yield by path analysis. This research was done via combined analysis split plot factorial experiment based on randomized complete blocks design with three replications along 2015-16 and 2016-17. The main factor included different level of canola genotype (Hy-ola401, RGS003, Jerry) and sub factors consisted different concentration of gibberellin hormone (0, 50 and 100 mg.l-1) and different time of application of gibberellin hormone (Planting, vegetative phase before flowering, flowering until pod emergence). Correla-tion between traits revealed the most positive and significant relation between biologic yield (r=0.960**), number of pod per plant (r=0.931**), number of seed per pod (r=0.905**), 1000-seed weight (r= 0.834**), pod length (r= 0.824**), harvest index (r= 0.690**) and seed yield was observed. Also the traits of leaf dry weight (r=0.550*), stem dry weight (r=0.530*) and plant height (r=0.510*) had significant correlation with the seed yield at 5 percent probability level. Stepwise regression analysis introduced five selected traits (biologic yield, number of pod per plant, number of seed per pod, 1000-seed weight and pod length determines) that covered 93.5 percent of variation related to seed yield. Variable of the biological yield with a positive direct effect (0.785) on seed yield with indirect effects of number of pods per plant (0.130), number of seed per pods (0.025), 1000-seed weight (-0.030) and pod length (0.05) caused a positive correlation between this trait and seed yield. So breeders can use selected traits for achieve opti-mum genotypes instead of direct selection for seed yield. Among studied traits, biologic yield had the most direct positive effect (0.785) on seed yield and had an important role to explain seed yield variation.

Drought stress is the main challenges in turf cultivation and management Introducing of drought resistant species in warm climate in Khozestan province, Iran is in high priority for solving this problem. Seven amenity grass species as Cynodon dactylon, Dichondra repens, Festuca arundinaceae (cv. Finelawn, Starlette and Talladega), Festuca rubra (cv.Napoli and Simone), Lolium perenne (cv. Capri, Danilo and Delaware), Poa pratensis (cv. Mardona) and two cv. Sport seed provided from Italy and Netherlands were subjected to four levels of drought stress in both laboratory and pots. In greenhouse Seeds were sown in pots and exposed to outdoors and in labratory seeds were sown in petri. A factorial experiment was conducted using four levels of water stresses namely well-watered (100% of field capacity) as control, (80%FC, 60%FC and 40% FC) in greenhouse condition and well-watered (0MPa) as control, (-0.3 MPa and -0.6 MPa and -0.9 MPa) in laboratory condition as the first factor and turf grass species as the second factor on a Completely Randomized Design (CRD) with 3 replications in 2018, Ahvaz, Iran. Data collected for 14 physiological traits of the seedlings. The result of analysis of variance showed significant effects of species and water stress levels for all of the traits (p<0.01). The species by water stress interaction effects were significant for all of the traits except contine of Catalase in Glasshouse condition indicating that the grass species had different responses to water stress. Results of means comparison between water stress levels showed in pots condition the values of RWC, recovery after drought and regrowth after cutting were decreased by drought stress and the lower values were observed in 40%FC. The higher values of (RWC), carbohydrates, Proline and Catalase, SOD and APX content were obtained in Cynodon dactylon, indicating that this species was more tolerated to drought stress than the other species. The was recommended for cultivation in green space of Iran. Turf quality and chlorophyll content was decreased due to drought stress. Proline content was increased in three species with prolonged withholding irrigation. The highest prolin content was observed in Cynodon dactylon in 80% FC.There was significant difference in activities of superoxide dismutase and catalase between stressed plants and control plants. The highest activities of these enzymes were showed in Cynodon dactylon.

A 7-years (2006−2012) field study was carriedout at the agriculture research station of Baikola, Neka, Iran;theexperiment included treatments varying in: (1) wheat straw management: plus residue (+R) and minusresidue(-R);(2)tillage system: zero tillage (ZT) andconventional tillage(CT); and (3) N rates:0(control),100,200and300 kg N ha-1 (N1-N4).After 7 years of continuous practice, ZT produced 40% greater maize seed yieldthan CT, whereas +R increased seed yield by 33% compared to -R. Seedyield of maize increasedwith N rate up to N3. Soil moisturecontent was higher under ZT than CT and with +R than -R in the0–15 cm depth, with the highest moisture content in the ZT+R treatment in many cases. After seven crop seasons, total organic C (TOC) and N (TON), respectively, were greater by 1.275 Mg C ha-1 and 0.031 Mg N ha-1 with +R than -R, and also greater by 0.563 Mg C ha-1 and 0.044 Mg N ha-1 under ZT than CT. There was no effect of tillage, straw and N fertilization on the NH4-Nin soil in mostcases, but +R treatment had higher NO3-N concentration in the 0–15 cm soil than -R. The NO3-N concentration inthe soil layers increased (though small) withincreasing N rate.The +R treatment had 6.7% lowerproportion of fine (38.0 mm) dry aggregates, and 4.5 mm largermean weight diameter (MWD) compared to -R treatment.Organic C, total N, moisture, aggregates stability, mechanicalresistance, pH and ECwere the factors that defined the differencein soil quality between conventional tillage and zerotillage.The principal component combining the variables organic C, total N, aggregate stability and moisture content showed the highest correlations with final yield (R = 0.87 for maize).The findingssuggest that ZT+R would improve some soil properties, andmayalso be better for the sustainabilityof high crop production. Nitrogen fertilization, althoughimproves crop production and some soil qualityattributes, it also increases the potential forNO3-Nleaching especially when applied inexcess of crop requirements for optimum yield.

Sweet corn faces challenges such as drought stress, which can signifi-cantly reduce yield. Zeolite and magnetic fields are emerging methods proposed to enhance plant growth and yield.

This study investigates the combined effects of zeolite and magnetic fields on sweet corn to develop optimal strategies for addressing drought stress, with a fo-cus on yield and physiological characteristics.

A split-plot factorial experiment was conducted within a randomized com-plete block (RCBD), featuring three replications. The experimental factors included three levels of drought stress (60%, 80%, and 100% of crop water requirement), two levels of zeolite application (0 and 5 Ton.ha-1), and five magnetic field treatments (50 and 100 mil-liTesla for 15 and 30 minutes, plus an untreated control).

Results demonstrated that the maximum cob length and thousand-grain weight were achieved under 100% drought stress with zeolite application and a magnetic field in-tensity of 15-100 milliTesla. Fresh yield and canned product yield were optimized under 80% drought stress with a magnetic field intensity of 15-100 milliTesla. The highest leaf area index (LAI) and crop growth rate (CGR) were recorded in the treatment involving 80% drought stress, zeolite, and a magnetic field intensity of 15-50 milliTesla. Net assimila-tion rate (NAR) and the percentages of starch and protein were significantly influenced by the interactions among drought stress, zeolite, and magnetic fields.

These findings highlight the positive effects of zeolite and magnetic field treatments on both quantitative and qualitative traits of sweet corn under varying wa-ter stress conditions, suggesting their potential for optimizing sweet corn cultivation practices.