Blossom-end Rot Incidence of Tomato as Affected by Irrigation Quantity, Calcium Source, and Reduced Potassium

Abstract

<jats:p>`Equinox' tomatoes (<jats:italic>Lycopersicon esculentum</jats:italic> Mill.) were grown during the springs of 2001 and 2002 with black polyethylene-mulch and drip irrigation on an Arredondo fine sand in Gainesville, Fla., to study the influence of water quantity, Ca source, and reduced K on incidence of blossom-end rot (BER), marketable fruit yield, and fruit and leaf Ca concentration. Tensiometers were used to schedule irrigation in main plots when the soil matric potential reached 10 or 25 kPa. Subplot nutritional treatments were no added Ca, Ca(NO<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>, Ca thiosulfate, CaCl<jats:sub>2</jats:sub>, CaSO<jats:sub>4</jats:sub>, and K rate reduced by 50%. Interactions between year and treatment were significant. During 2001, total marketable yields were higher with Ca(NO<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub> or CaCl<jats:sub>2</jats:sub> compared to plants that received Ca thiosulfate and were higher from plants irrigated at 10 kPa than irrigated at 25 kPa. Number and weight of BER fruit were lower with Ca(NO<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub> and reduced K than with no added Ca and CaSO<jats:sub>4</jats:sub>. Leaf and fruit Ca concentrations were generally higher with Ca(NO<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub> compared to all other nutritional treatments. Leaf and fruit Ca concentrations were generally higher from plants irrigated at 10 kPa than at 25 kPa. The reduction of NH<jats:sub>4</jats:sub><jats:sup>+</jats:sup>-N, by the supply of N as NO<jats:sub>3</jats:sub><jats:sup>-</jats:sup>, and the addition of supplemental Ca reduced the incidence of BER, and increased the leaf and fruit Ca concentrations. During 2002, marketable yields were higher with CaSO<jats:sub>4</jats:sub> than with CaCl<jats:sub>2</jats:sub> and reduced K. Weight and number of BER fruit were lower with irrigation at 10 kPa than at 25 kPa. Leaf and fruit Ca concentrations were higher or similar from plants that received Ca(NO<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub> than with all other nutritional treatments. During the 2002 season, rainfall was less and temperatures and daily evapotranspiration (ET) were higher than in the 2001 season. In the 2002 season, 3.28 × 10<jats:sup>6</jats:sup> L·ha<jats:sup>-1</jats:sup> of irrigation was applied as compared to 1.58 × 10<jats:sup>6</jats:sup> L·ha<jats:sup>-1</jats:sup> in 2001. With an average Ca concentration of 76 mg·L<jats:sup>-1</jats:sup> in the irrigation water, much more Ca was applied during the higher ET 2002 season. With the higher transpiration and temperature, water uptake and hence, Ca uptake were increased. During both seasons, the lowest Ca concentration was observed at the blossom end of the fruit and the highest Ca at the stem end of the fruit. Fruit Ca concentrations were lower and BER was 5 times higher in the lower ET, higher rainfall (lower irrigation) 2001 season compared to the higher ET, lower rainfall (higher irrigation) 2002 season. These data support that BER was a symptom of Ca deficiency and this deficiency was aggravated by high rainfall, low ET, and the resulting reduced irrigation applied and reduced Ca uptake.</jats:p>

Comparative effect of partial root-zone drying and deficit irrigation on incidence of blossom-end rot in tomato under varied calcium rates

“…Earlier studies have frequently observed that soil moisture stress can stimulate BER development (e.g. Adams and Ho, 1993), and reduced irrigation practices often result in a greater incidence of BER in tomatoes (Reid et al ., 1996; Franco et al ., 1999; Taylor et al ., 2004). It is well known that Ca movement in the plants and accumulation in the fruit are tightly linked with the transpiration rate of the plants (Keiser and Mullen, 1993).…”

“…It is well known that Ca movement in the plants and accumulation in the fruit are tightly linked with the transpiration rate of the plants (Keiser and Mullen, 1993). Basically, a decrease in plant transpiration rate could reduce plant total Ca uptake, and may thus increase BER occurrence in tomato (Taylor et al ., 2004) and sweet pepper (Tadesse et al ., 2001). However, as the leaf possesses a higher transpiration rate than the fruit, it often acts as a competing sink with the fruit for directional Ca flow and accumulation (McLaughlin and Wimmer, 1999; Taylor et al ., 2004).…”

“…Although there is a general consensus that tomato fruits are hydraulically isolated from the xylem stream and therefore may be inaccessible for the root-sourced ABA signalling, particularly at later stages of fruit development (Davies et al ., 2000), studies have demonstrated that, during the early stage of fruit growth, soil water deficit treatment or exogenous ABA application could stimulate xylem development in the fruits (Davies et al ., 2000; Tonetto de Freitas et al ., 2011). Despite the possible effect of ABA in reducing BER incidence, previous studies have indicated that low plant water status is associated with a low number of functional xylem vessels in tomato fruits (Belda and Ho, 1993), and reduced irrigation increases BER occurrence in tomatoes (Adams and Ho, 1993; Taylor et al ., 2004). Consistent with this, Zegbe et al .…”

“…Blossom-end rot (BER) is a physiological disorder in tomato ( Solanum lycopersicum L. ) fruit that may reduce the marketable yield by up to 50% (Taylor et al ., 2004). Although a high rate of BER occurrence has often been associated with low calcium (Ca) content in the fruit tissue (Ho and White, 2005), total tissue Ca content is not a precise predictor of BER development, and the Ca content for fruit with BER symptoms may be equal to or higher than that for healthy fruit (Nonami et al ., 1995; Saure, 2001).…”

Soil Salt Distribution and Tomato Response to Saline Water Irrigation under Straw Mulching

“…On the contrary, excessive water supply leads to the spindling of tomatoes, limits the tomato physiological and reproductive growth, finally causes a low tomato yield [39–40]. In addition, water supply has certain connections with the tomato BER i , while water whether to directly affect the BER i is still not fully understood [41]. Besides, under the condition of irrigation combined with mulching, soil salt was found to move towards the edge of the mulch, thus the salinity within the plant root-zone was decreased, which created a suitable environment for the growth of tomato [42].…”