Response of White Perilla’s Yield, Water Productivity, Consumed Energy and Farm Income to Irrigation Treatments in Sandy Soil

Abstract

White perilla (Perilla frutescens) is not a widely grown commercial crop in Egypt and no information is available on water requirements of the crop under Egyptian conditions. Therefore, a field experiment was conducted in a private farm (30^o40' N latitude, 32^o15' E longitude, and 10.0 m above mean sea level), Ismailia Governorate, Egypt, during the 2022 and 2023 summer growing seasons. The objectives of this field experiment were to test the effect of six irrigation treatments (I_Farmer, I_Growth-stage, I_120%ETo, I_100%ETo, I_80%ETo, and I_60%ETo) on perilla seed yield, plant height, total carbohydrates (TC, %), total protein (TP, %), total oil content (%), macro-, secondary-, micro-nutrients, amounts of applied irrigation (AIW, m³/ha), water productivity (WP, kg seed/m³ applied water), yield response factor (Ky), energy consumption, and farm income. Results showed significant effect of the irrigation treatments on all tested parameters. The 2-year average AIW values were 9653, 7259, 6540, 5450, 4360, and 3270 m³/ha for I_Farmer, I_Growth-stage, I_120%ETo, I_100%ETo, I_80%ETo, and I_60%ETo treatments, respectively. The highest 2-yr. average seed yield of 4.979 t/ha was recorded for the I_Growth-stage treatment, while the lowest value of 2.890 t/ha was recorded for the I_{60% ETo} treatment. Results revealed also that, there were no significant differences between seed yields recorded for I_Growth-stage and I_120%ETo treatments in the two seasons. The 2-yr average WP values were 0.406, 0.686, 0.686, 0.713, 0.8, and 0.884 kg seeds/m³ for the I_Farmer, I_Growth-stage, I_{120% ETo}, I_{100% ETo}, I_{80% ETo}, and I_{60% ETo}, respectively. Perilla Ky value was 0.778 indicating moderately tolerant to deficit irrigation. The highest 2-yr average value of consumed electric energy of 4924 kW was recorded for farmer practice (I_Farmer), while the lowest average value of 1669 kW was recorded for the I_{60% ETo} treatment. The 2-yr average values of cost: benefit ratios were 1.50, 1.10, 1.20, 1.31, 1.43, and 1.90% for the same respective irrigation treatments. From the obtained results it could be concluded that, applying appropriate agronomic practices (e.g. proper amounts of irrigation water and applying fertilizer through drip-fertigation technique) can achieve high perilla seed yields. In case of water shortage, applying good agricultural practices and I_120%ETo can save 32.2% (3113 m³/ha) of applied irrigation water without significant reduction in seed yield, achieve 4.485 t/ha of see yield, water productivity of 0.686 kg seed/m³, save 32.3% of electric energy, and 14.3% higher net income compared with farmer practice.

Keywords: Applied water, water productivity, yield response factor, electric energy, farm income