Fruit Yield and Quality, and Irrigation Water Use Efficiency of Summer Squash Drip-Irrigated with Different Irrigation Quantities in a Semi-Arid Agricultural Area

Fruit yield, yield components, fruit mineral content, total phenolic content, antioxidant activity and irrigation water use efifciency （IWUE） of summer squash responses to different irrigation quantities were evaluated with a ifeld study. Irrigations were done when the total evaporated water from a Class A pan was about 30 mm. Different irrigation quantities were adjusted using three different plant-pan coefifcients （Kcp, 100% （Kcp1）, 85% （Kcp2） and 70% （Kcp3））. Results indicated that lower irrigation quantities provided statistically lower yield and yield components. The highest seasonal fruit yield （80.0 t ha-1） was determined in the Kcp1 treatment, which applied the highest volume of irrigation water （452.9 mm）. The highest early fruit yield, average fruit weight and fruit diameter, length and number per plant were also determined in the Kcp1 treatment, with values of 7.25 t ha-1, 264.1 g, 5.49 cm, 19.95 cm and 10.92, respectively. Although the IWUE value was the highest in the Kcp1 treatment （176.6 kg ha-1 mm-1）, it was statistically similar to the value for Kcp3 treatment （157.1 kg ha-1 mm-1）. Total phenolic content and antioxidant activity of fruits was higher in the Kcp1 （44.27 μg gallic acid equivalents （GAE） mg-1 fresh sample） and in the Kcp2 （84.75%） treatments, respectively. Major （Na, N, P, K, Ca, Mg and S） and trace （Fe, Cu, Mn, Zn and B） mineral contents of squash fruits were the highest in the Kcp2 treatment, with the exception of P, Ca and Cu. Mineral contents and total phenolic content were signiifcantly affected by irrigation quantities, but antioxidant activity was not affected. It can be concluded that the Kcp1 treatment was the most suitable for achieving higher yield and IWUE. However, the Kcp2 treatment will be the most suitable due to the high fruit quality and relatively high yield in water shortage conditions.

Determining Crop and Pan Coefficients for Cauliflower and Red Cabbage Crops Under Cool Season Semiarid Climatic Conditions

The aim of this study was to estimate the evapotranspiration of cauliflower and red cabbage crops grown under cool season semiarid climatic conditions from Class A pan evaporation. Actual evapotranspiration （ETc） of cauliflower and red cabbage crops was calculated according to the water balance approach. Reference evapotranspiration （ETo） was calculated with FAO Penman-Monteith equation. Pan evaporation （Epan） was measured by using Class A pan. Seasonal ETc was determined as 475 mm for cauliflower and 556 nun for red cabbage. Seasonal pan coefficient （kp=ETo/Epan） was determined as 0.82, and the seasonal crop coefficient （kc=ETc/ETo） was determined as 0.84 for cauliflower and 0.83 for red cabbage. So the evapotranspiration of cauliflower and red cabbage crops was estimated as 70% Class A pan evaporation.

Physical and mechanical properties of some hybrid corn varieties

The aim of this study was to determine the structural designing parameters of silo and bins used for storage of some hybrid corn varieties(Zea mays L.).In the research,three corn varieties-dentcorn(Zea mays indentata Sturt.),popcorn(Zea mays everta Sturt.),sweetcorn(Zea mays sacharata Sturt.)-widespread cultivated in Turkey were used.Physico-mechanical parameters(bulk density,true density,angle of internal friction,static coefficient of friction)were considered as the dependent variables,and moisture content(8%,10%,12%,and 14%)as the independent variable.The bulk density,true density and angle of internal friction varied from 608.46 to 856.46 kg/m^(3),950.88 to 1110.89 kg/m^(3),and 25.2°to 34.2°,respectively,with the increase in moisture content from 8% to 14%.According to results of the research,the highest average value for bulk density,true density,angle of internal friction were found in popcorn variety(839.17 kg/m^(3)),popcorn variety(1074.40 kg/m^(3)),sweetcorn variety(30.50°),respectively.The highest average value for static coefficient of friction at concrete surface(C30)was recorded in dentcorn variety(0.662).