Impact of water stress on citrus yield

Abstract

Water shortage is becoming a severe problem in arid and semi-arid regions worldwide, reducing the availability of agricultural land and water resources. Deficit irrigation strategies can improve water-use efficiency and the sustainability of agro-ecosystems, although it is important to model the effects on yield loss due to irrigation water restrictions. This work estimates the water production function in citrus trees, determining the relationship between plant water stress and yield depression, as well as establishing a mathematical model for each phenological stage considered (flowering, fruit growth and ripening), and for the entire productive process. For three consecutive years (2006)(2007)(2008), four regulated deficit irrigation treatments plus a control (100% crop water evapotranspiration (ET C )) were implemented in 13-year-old citrus trees (Citrus sinensis L. Osb. cv. Navelina). Different water production functions were determined for each phenological stage, establishing the relationship between the irrigation water stress and crop yield. Our results show that the fruit growth and flowering stages were the most sensitive periods in relation to irrigation water deficit and yield loss. Water stress close to 50% of ET C during the flowering stage would impose a yield loss of up to 20%, whereas this same water stress level during the fruit growth or ripening stages would result in yield losses of nearly 10% and 6%, respectively. The adjustment with cross terms (r 2 =0.87) estimated the yield loss with good accuracy, being very similar to data measured in each study season. Consequently, the combined effect of deficit irrigation in different stages would be an additive-multiplicative model, considering that the effect of water stress in previous periods determined the crop yield response. Our model indicated that the crop water production function under deficit irrigation programmes would have a quasi-linear relation for water deficits below to 40% ET C . The previous model functions did not enable us to establish an accurate relationship when the water stress was applied in different phenological stages. Thus, this new interpretation is valuable to improve our knowledge and predict the impact of regulated deficit irrigation and have potential application in precision water stress and sustainable irrigation scheduling for citrus.

Fruit Yield and Quality of ‘Valencia’ Orange Trees under Long-Term Partial Rootzone Drying

“…Interestingly, crop load and especially cropping efficiency were similar in all treatments, including DI. This general lack of irrigation effect agrees with previous observations on drip-irrigated 'Tarocco' [42,59] and navel oranges under PRD [60], and 'Navelina' oranges under DI [25], but is apparently inconsistent with other studies in citrus where yields were reduced by deficit irrigation [21,23,36,44,61].…”

Adoption of improved citrus orchard management practices: a micro study from Drujegang growers, Dagana, Bhutan

“…Moreover, most of the orchards are not only located in slopes of varying gradient but also away from water source. Water stress in citrus reduces the yield considerably (30 %) [33]. Under Drujegang condition, the driest months of the year (January, February and March) coincides with flowering stage while delay in onset of monsoon (dry period-April through May) and rising temperature (28-36 °C) coincide with fruit cell division stage.…”

Influence of ethylene and ethephon treatments on the peel color and carotenoids of Gannan Newhall navel orange during postharvest storage

“…Citrus fruit is one of the highest yield fruits in the world with an annual output of 10 9 kg. It is the third largest international trade of agricultural products in the world, after wheat and corn (Garcia‐Tejero, Hugo Duran‐Zuazo, Arriaga‐Sevilla, & Luis Muriel‐Fernandez, ). Gannan planting area is about 1.26 × 10 9 m 2 and its output of Gannan Newhall navel orange has reached 1.5 × 10 9 kg in 2013, which ranked the first in navel orange acreage worldwide (Xiao, Yan, Peng, & Fang, ).…”