White plastic and deficit irrigation improve pomegranate production

Authors: Wang, Dong; AYARS, JAMES - Retired ARS Employee; MAKUS, DONALD - Former ARS Employee

Submitted to: International Journal of Fruit Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2021
Publication Date: 7/12/2021
Citation: Wang, D., Ayars, J.E., Makus, D. 2021. White plastic and deficit irrigation improve pomegranate production. International Journal of Fruit Science. 21(1):868-882. https://doi.org/10.1080/15538362.2021.1939228.
DOI: https://doi.org/10.1080/15538362.2021.1939228

Interpretive Summary: Production of many fruit crops in arid or semi arid climate incurs high cost of irrigation and weed control. In a multi-year field study, we evaluated pomegranate yield, quality, tree growth and physiological responses to covering the in-rows with a white plastic tarp and super-imposed with deficit irrigation treatments. Pomegranate fruit yield and quality were improved with the tarp cover as compared to bare ground. Deficit irrigation did not impact yield of prime fruit. Covering the orchard in-rows with white plastic and irrigating at reduced rates can improve pomegranate production.

Technical Abstract: Developing improved water management strategies and on-farm cultural practices are important in reducing pomegranate (Punica granatum L. cv Wonderful) production costs. A pomegranate orchard established in 2010 was irrigated at water replacement rates of 35, 50 and 100% of crop evapotranspiration from 2013 to 2016. A durable white plastic tarp was installed in one half of each water replacement plot to evaluate the added benefits to soil moisture retention, weed control, and plant growth and yield. Edaphic orchard floor conditions such as light reflectance into the lower tree canopy, mid-day soil surface temperature, soil water content, and average daily soil temperatures were moderated or improved by the plastic cover. Phenological changes such as leaf greenness, trunk basal suckering, and trunk diameter were generally enhanced by increased water application rates and plastic use. Marketable and total fruit yields increased by an average of 22% and 25% from 2013 to 2016, with the use of plastic cover compared to bare soil. Total fruit yield increased linearly with increasing water replacement rates. Neither the white plastic nor irrigation rates improved external fruit color. Fruit raw product attributes were little changed by treatments; however, increasing water application rates or using plastic cover resulted in darker juice color. Increased basal suckering was observed with plastic cover compared to the bare grounds.