What struck Efrayim?
Radak: Their enemies.
What is the significance of their root drying?
Radak: They are compared to a tree that its root dried - it will not make more fruits.
Radak citing Targum Yonasan: Yisrael are like a date tree, that its root below dried...
Malbim: I need not give to them a womb that causes miscarriages - automatically [they will not give birth], for Efrayim was stricken and their root dried.
Will they not make fruits?
Rashi: It is not good for them to reproduce - "even if they will give birth, I will kill the desired [fruits] of their womb."
Radak: Correct - "mi'Ledah umi'Beten ume'Herayon" (11).
Radak citing Targum Yonasan: Its foliage above will not make Nov. Nov is vegetation or a flower. Yonason translates "Tzemach Bli Ya'aseh Kemach" (8:7) 'Nov Lo Yabed.' A Mishnah (Avodah Zarah 48b) says 'because the Neviyah [gets detached and] falls on them.' 'Me'ilah applies to wood, but not to shavings and Neviyah' (Me'ilah 14a).
Malbim: Correct. If a tree's root died, based on nature it cannot bear fruits, even without punishment of Hashgachah.
Why does it add "v'Hemati Machamadei Vitnam"?
Malbim: Even if by chance they will give birth, I will kill the desired [fruits] of their womb - punishment of Hashgachah.