Effect of fruit load on the water balance of melon plants infected with Monosporascus cannonballus

Advances in the Biology and Management of Monosporascus Vine Decline and Wilt of Melons and Other Cucurbits

“…Stomatal conductance was similar in plants with 1 fruit or with 4-6 fruits. Moreover, after maturation and removal of the only fruit in the 1-fruit plants, the stomatal conductance decreased to the levels measured in leaves of plants without fruits (Pivonia et al 2002a). Thus, presence of even one maturing fruit was enough to maintain a relatively high leaf stomatal conductance in melon.…”

“…Thus, the association between fruit load and plant collapse probably is related to other processes that also are involved in the regulation of plant water balance, and tyloses restrict water flow exacerbating the situation. Pivonia et al (2002a) found that fruit removal in healthy melon plants caused an immediate and sharp drop in leaf stomatal conductance. When young fruits were regularly removed, leaf stomatal conductance remained low and prevented wilting ( Fig.…”

“…Lee (2004) found that removal of fruit from melon plants infected with M. cannonballus resulted in an increase in a number of sugars in the roots, which, in turn, reduced disease severity, concluding that increased sugars allowed for greater root growth that could resist disease better. Enhanced root growth and increased root sugars due to frequent fruit removal might explain reduced plant wilting in M. cannonballusinfected melon plants as fruit removal even from plants showing early wilt symptoms resulted in plant recovery (Pivonia et al 2002a) (Fig. 2.1).…”

“…Despite the low root xylem hydraulic conductance, plants without fruits did not collapse (Pivonia et al 2002a). Thus, the association between fruit load and plant collapse probably is related to other processes that also are involved in the regulation of plant water balance, and tyloses restrict water flow exacerbating the situation.…”

Greenhouse Evaluation of Melon Rootstock Resistance to Monosporascus Root Rot and Vine Decline as Well as of Yield and Fruit Quality in Grafted ‘Inodorus’ Melons

“…Moreover, they reported that the progression of symptoms of MRR/VD is affected by fruit load and maturity stage. Fruit removal reduced leaf stomatal conductance and increased root growth, thus enabling the plants to survive (Pivonia et al, 2002). The lighter fruit (average 1.2 kg) in the autumn cultivation was also considered to be one factor associated with slower progression and less severity of disease symptoms (average 1.6 kg in the summer cultivation).…”