0
points
CUCUMBER LEAVES BUNCHING UP

Cucumber    None Given

Hi,

We are cultivating Seedless Cucumbers in Cocopeat Growbags under polyhouses as the soil is heavily infested with root knot nematodes.

We had noticed that our plants have started increasingly showing abnormal growth (it is increasing/spreading), photos attached. We are noticing that the leaves become dark green and start bunching on top together. we have tried treating with excess boron and micro-nutrients, but the problem is spreading.

we have shown it to local experts but they have been unable to identify the issue. Can someone advise as to whether the issue is nutrient problem or some disease??


Posted by: GIRISH ANEJA (1 point) GIRISH ANEJA
Posted: December 10, 2016


David Hughes commented,
Where are you?
over 2 years ago.



Answers

1
point
This looks like excess fertilizer which leads to too much salt in the leaf. Cucumber are very susceptible to this. I am posting some excellent content from the New South Wales Government in Australia. http://www.dpi.nsw.gov.au/agriculture...


"Excess fertiliser (excess salt)
Cucumbers are sensitive to excess fertiliser, which increases soil salinity and causes toxicity, usually from nitrogen. Plants grown under saline conditions, where the soil or growing medium has high electrical conductivity (EC), are stunted and produce dark green, dull, leathery leaves that are prone to wilting. A narrow band of yellow necrotic tissue is often present on leaf edges. This can affect leaf expansion, causing a slight downward cupping of the leaf. After a serious water stress, the oldest leaves may develop a uniform pale green chlorosis and small necrotic areas within the leaf. If water supply is maintained, leaves may only develop a band of pale green tissue around their edges. Plants are likely to wilt in warm weather.
Treatment
Leach the soil or growing medium with fresh water until the excess fertiliser is removed. Adjust the fertiliser program to ensure that rates do not exceed crop needs."


You mentioned that you gave extra boron

The same source says this about Boron toxicity

"Cucumber plants are very sensitive to high boron levels. In fact, boron compounds have been used as herbicides.
Boron toxicity is indicated by yellowing between the veins of older leaves. This is followed quickly by the development of small, brown necrotic spots, which eventually join to form large areas of dead tissue. At the same time, the newer leaves become chlorotic and are distorted because of damage in the bud. Few female flowers may develop.'


You should check for these brown spots.

I think you should try washing the soil out to remove the access fertilizer.


Posted by: David Hughes (36 points) David Hughes
Posted: December 11, 2016


GIRISH ANEJA commented,
Thnx David!! the only issue with excess fertilizer is that the nearby plants are growing fine, rather they are showing Magnesium deficiency.. But there might be some issue with drippers and i will certainly check the ec readings of the affected bags to see if they are on the higher side..
over 2 years ago.



0
points
In my opinion you still have nematodes problem, to be sure you can check the roots of your cucumber and see if there's root knot or not; you have to apply nematicides like Vydate (Oxamyl).... and you have to add products that can encourage the rooting system like phosphorus and organic matter, and to apply by foliar amini acids and micronutrients.


Posted by: Mohammad Kafafi (1 point) Mohammad Kafafi
Posted: December 10, 2016


GIRISH ANEJA commented,
No Nematodes!! I had stated in begining that we are growing in cocopeat growbags..
over 2 years ago.

Mohammad Kafafi commented,
I know that you stated in beginning that you are growing in cocopeat growbags, but I understand that you put the growbags in the same infected soil, isn't it?, nematodes are micro worms they may translocated from the infested soil to the growbags or through the water..... Just please check the roots
over 2 years ago.



0
points
This looks more like potassium deficiency (the fruit abnormality and the leaf round burning). A small does of potassium sulfate would help. Worth a try


Posted by: Mohamad Safieddine (1 point) Mohamad Safieddine
Posted: December 11, 2016


Mohamad Safieddine commented,
Also the magnesium deficiency is true. Again magnesium sulfate is enough
over 2 years ago.



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