How Planting Density Affects Number and Yield of Potato Minitubers in a Commercial Glasshouse Production System

Abstract

Commercial potato minituber production systems aim at high tuber numbers per plant. This study investigated by which mechanisms planting density (25.0, 62.5 and 145.8 plants/m 2 ) of in vitro derived plantlets affected minituber yield and minituber number per plantlet. Lowering planting density resulted in a slower increase in soil cover by the leaves and reduced the accumulated intercepted radiation (AIR). It initially also reduced light use efficiency (LUE) and harvest index, and thus tuber weights per m 2 . At the commercial harvest 10 weeks after planting (WAP), LUE tended to be higher at lower densities. This compensated for the lower AIR and led to only slightly lower tuber yields. Lowering planting density increased tuber numbers per (planted) plantlet in all grades. It improved plantlet survival and increased stem numbers per plant. However, fewer stolons were produced per stem, whereas stolon numbers per plant were not affected. At lower densities, more tubers were initiated per stolon and the balance between initiation and later resorption of tubers was more favourable. Early interplant competition was thought to reduce the number of tubers initiated at higher densities, whereas lateroccurring interplant competition resulted in a large fraction of the initiated tubers being resorbed at intermediate planting densities. At low planting densities, the high number of tubers initiated was also retained. Shortening of the production period could be considered at higher planting densities, because tuber number in the commercial grade > 9 mm did not increase any more after 6 WAP.

Furrow-irrigated chufa crops in Valencia (Spain). I: Productive response to two irrigation strategies

“…The end of the chufa irrigation period was considered to be the time when the straw was burned, before tuber harvesting. In this study, the dates of straw burning were November 2 The harvest index (HI) was calculated for each sampling as the ratio of tuber yield to total biomass, including the root system, on a dry matter basis (g g -1 ; Van der Veeken & Lommen, 2009).…”

Response of drip-irrigated chufa (Cyperus esculentus L. var. sativus Boeck.) to different planting configurations: Yield and irrigation water-use efficiency

“…The plant height was measured, and plants were divided into their parts and analysed separately: (i) shoots and all of their leaves (hereinafter referred to as 'leaves') and (ii) tubers. After washing, each sampled plant part (leaves or tubers) was weighed, and after being dried at 65ºC in a forced-air oven (Model 297; JP Selecta, Barcelona, Spain) for four days to obtain the dry weight and the harvest index, the ratio of tuber to total biomass was calculated on a dry matter basis (Van der Veeken and Lommen, 2009). At harvest, the fresh average tuber weight was determined by counting and weighing tubers from a sample of approximately 500 g. The IWUE was calculated as the relationship between the yield and the I applied (Tolk and Howell, 2003).…”

Sera Koşullarında İleri Patates Hatları ve Çeşitlerinin Mini Yumru Performanslarının Belirlenmesi

“…Son yıllarda ticari üretimlerde büyük mini yumruların (10g ve üstü) üretimi tercih edilmektedir. (Van der Veeken and Lommen, 2009). Patateste mini yumru sayısı ve büyüklüğünü etkileyen bitki sıklığı mekanizmaları ile ilgili bilgilerin sınırlı olduğu ve yeni araştırmaların yapılması gerektiği bildirilmiştir (Van der Veeken and Lommen, 2009).…”